Centrifugal dispensing device

ABSTRACT

A centrifugal dispensing device particularly adapted to intermittent application of a selected liquid such as glue, paint and the like. The device includes a disc positioned to rotate in a horizontal plane. Conduits are provided for feeding selectively supplies of the selected liquid and a solvent therefor to the disc. A shield is movably disposed so as to be selectively interposed between the disc and the work. Means are provided for moving the shield to a position between a work piece and the disc when solvent is applied to the disc, and for moving the shield away when the selected liquid is applied to the disc.

United States Patent 1 Crathern 1451 July 31,1973

1 1 CENTRIFUGAL DISPENSING DEVICE [75] Inventor: Charles F. 11.Crathern, Hopkinton,

[73] Assignee: Crathern Engineering Company,

Contoocock, NH.

[22] Filed: June 23, 1972 [21] Appl. No.: 265,735

[52] US. Cl 239/224, 239/104, 239/121 [51] Int. Cl 1305b 3/10,'B05b H28[58] Field 01 Search 239/223, 224, 7, 239/104, 120-122, 288.3, 288.5

[56] References Cited UNITED STATES PATENTS 1,330,218 2/1920 Richer239/223 1,779,336 10/1930 Riley 239/224 X 2,587,083 2/1952 Andermatt239/223 FOREIGN PATENTS OR APPLICATIONS 1910 Great Britain 239/122Primary Examiner-Robert S. Ward, Jr. Att0rney-Robert .l. Schiller et al.

[57] ABSTRACT A centrifugal dispensing device particularly adapted tointermittent application of a selected liquid such as glue, paint andthe like. The device includes a disc positioned to rotate in ahorizontal plane.

Conduits are provided for feeding selectively supplies of the selectedliquid and a solvent therefor to the disc.

A shield is movably disposed so as to be selectively interposed betweenthe disc and the work. Means are provided for moving the shield to aposition between a work piece and the disc when solvent is applied tothe disc, and for moving the shield away when the selected liquid isapplied to the disc.

9 Claims, 3 Drawing Flgures CENTRIFUGAL DISPENSING DEVICE This inventionrelates to liquid dispensing devices, and more particularly tocentrifugal applicator particularly adapted for intermittent use, forexample, in application of glue, paint and the like.

Various industrial operations require intermittent application of aliquid to a work piece. For example, a typical system for formingcardboard cartons may include means for moving cardboard stock, a shaperfor cutting and folding the stock, a glue applicator, apparatus forclosing and pressing the glued stock, and means for removing thecompleted cartons from the machine. Operation of the various means isnormally intermittent, i.e., stepwise. Or an industrial operation mayinclude the intermittent application of paint, e.g., to work pieces asone operational step in a series of steps.

A principal problem encountered in the above systems involves theintermittent operation of the glue or paint applicator. Thisintermittent use frequently results in glue or paint becoming set orpartly set in the applicator and tends to contaminate subsequentapplications, all which may adversely effect subsequently glued seams,or subsequently painted surfaces. Also, the applicator. may becomeclogged with set or partly set glue or paint. If the entire machine thenhas to be shut down so that the applicator may be cleaned, it can betedious, time consuming and costly.

It is thus a principal object of this invention to provide an improvedapparatus and method for dispensing of liquids.

A further object is to provide an apparatus of the character describedwhich may be operated intermittently without clogging.

A more specific object is to provide an apparatus for intermittentapplication of selected liquid such as glue,

paint and the like which is self-cleaning between applications.

Still other objects will be obvious from the following detaileddescription.

Generally, to effect the foregoing and other objects the presentinvention is embodied in a centrifugal liquid applicator comprising adisc adapted to rotate in a horizontal plane about a substantiallyvertical shaft. Means are provided for selectively discharging aselected liquid and a solvent for the liquid onto the disc. A shield isdisposed outside the disc and is movable so as to be selectivelyinterposed between the disc and the work to thereby block the spray pathfrom the disc when solvent is being discharged thereon, and unblock thespray path when the selected liquid is being discharged thereon. Meansare also provided for collecting solvent sprayed onto said shield, andin a preferred embodiment for recycling at least a portion of thesolvent to the disc.

Other objects of the invention will in part be obvious and will in partappear hereinafter. The invention accordingly comprises the apparatuspossessing the construction, combination of elements, and arrangement ofparts which are exemplified in the following detailed disclosure, andthe scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the presentinvention, reference should be had to the following detailed descriptiontaken in connection with the accompanying drawings wherein:

FIG. I is a schematic crosssec'tion through a perspective, of anexemplary device embodying the principals of the present invention, inposition for applying a selected liquid;

FIG. 2 is a schematic cross-section through a perspective of the deviceof FIG. 1 in position for selfcleaning; and

FIG. 3 is an enlarged, plan view of an embodiment of shield for use inthe device of FIG. 1.

Referring now to the drawings, there is shown in FIGS. 1 and 2 anembodiment of the invention comprising a disc 20 having a cylindricalperiphery or rim 22, and flat solid radial support member 24 rigidlyconnecting rim 22 to central hub 26. Hub 26 is centrally apertured andpreferably keyed so that disc 20 can be fixed to shaft 28 for rotationeoaxially with the latter.

Support member 24 is provided with an annular groove 30 formed in onesurface of the support member 24 adjacent hub 26 and (as shown in FIG.3) preferably includes a plurality of generally axially extendingoutwardly flared, distributor vanes 32 formed on the same surface of thesupport member 24, disposed outwardly of cavity 30. The vanes, as willbe seen direct fluids which are fed into groove 30 radially outward bycentrifugal force when the disc is rotated at high speed about asubstantially vertical axis. As thus described disc 20 is a centrifugaldisperser well known in the art.

Shaft 28 is mounted in internal sleeve 34 of a preloaded bearing pair36, preferably of the doublex-type. The latter is mounted in acylindrical body 38. Means (not shown) such as an electric motor areprovided for rotating shaft 28.

The device includes a liquid supply and supply of solvent therefor. Asused herein the terms liquid and solvent therefor are intended toinclude true solutions, e.g., an aqueous based glue (in which case thesolvent therefor may be water) fluid suspensions of particulate matterin a carrier, e.g., an oil base pigment paint (in which case the solventtherefor may' be any commercially available paint thinner), thixotropicgels and solvents therefor, and other like materials. The'liquidsupplycomprises liquid holding tank 40-having inlet tube 42 through which theselected liquid can be introduced thereto, and liquid outlet tube 44coupled to tank 40 through solenoid, valve 46. Outlet-tube 44 extendsthrough body 38 and is disposed to discharge liquid into groove 30. Thesolventjsupplycomprises sol vent holdingtank 48 having inlet' tubeslIthrough which liquid solvent can be introduced thereto,fandsolventoutlet. tube 52 coupled to tank 48 throughjsolenoid valve 54. Solventoutlet tube 52 extends' through body 38 and has an end positioned todischarge solvent into groove 30.

The device also includes shield 56 which is coupled at one end thereofto body 38. Shield 56 is mounted for movement axially with respect toshaft 28 between a first position wherein the shield is positionedbetween the disc and the work and thereby blocks the centrifugal spraypath from the disc, as will be described in detail hereinafter, and asecond position wherein the shield is located out of the centrifugalspray path of the disc. To this end shield 56 is coupled to body 38 byvertically reciprocating piston rods of two double acting pneumaticactuators 58A and 588 which in turn are fixed to body 38. Positivepressure air for causing reciprocating movement of the piston rods ofactuators 58A and 58B is provided by air lines 60A and 60B incommunication with the top and bottom ends respectively of the cylinderof the actuators. The latter have piston rod strokes long enough to pullshield 56 out of the spray path of the disc as shown in FIG. 1 when therods are retracted and to provide sufficient clearance for the spraypath as shown in FIG. 2 when the rods are extended. Alternatively othermeans known in the art such as gear and ratchet means or solenoid meansmay be used for appropriately moving the shield.

Shield 56 also includes means such as an annular trough 62 fixed to, orformed integrally therewith, at or near the lower end thereof on theinner surface of the latter.

Mounted in the bottom of trough 62 is drain 64. The latter in turn iscoupled through solenoid valve 66 and flexible hose 68 to the input sideof suction pump 70. The output side of pump 70 is connected throughsolenoid valve 72 to drain line 74. The output side of pump 70 is alsoconnected through solenoid valve 76 to line 78 leading to the solventholding tank 48.

Exemplary operation of the invention for the intermittent application ofglue, tag, as may be encountered in forming cardboard boxes, can bereadily understood with reference to FIGS. 1 and 2 of the drawings.Referring first to FIG. 1, the device is connected so that shaft 28 issubstantially vertical. Shaft 28 is rotated at relatively high speed,e.g., l,800 to 5,000 rpm. A substan tially flat cardboard workpiece 80is moved into gluing position proximate shield 56 and is typicallyaligned with its surface substantially parallel to the central axis ofshaft 28. Valve 60B is opened causing the actuators to raise shield 56from a first position where it is interposed between the disc and theworkpiece 80 as shown in FIG. 2 to a second position as shown in FIG. 1.Valve 46 is opened, a predetermined quantity of liquid glue isdischarged through line into groove 30, and valve 46 is then closed.Since the disc is rotated at high speed, the liquid gluein groove 30will be forced outward by centrifugal force and will be thrown off as aspray from the disc at its periphery or rim onto the workpiece 80 (i.e.,along the spray path indicated by line 79). Once substantially all theglue discharged into groove 30 has been thrown off the disc, valve 60Ais opened causing the actuators to move shield 56 to its first position,i.e., interposed between disc 20 and workpiece 80, wherein it blocks anyliquid which may be sprayed from the rotating disc 20 by centrifugalforce. Valve 54 is then opened, a predetermined quantity of glue solventis discharged through line 52 onto cavity 30, and the valve is closed.The solvent serves to dissolve glue that may still be adhered to thedisc. Solvent, with dissolved glue, is thrown off the disc at itsperiphery by centrifugal force, onto the inner surface of shield 56(i.e., along the spray path 79) and also thus serves to clean glue fromboth the disc and the shield. The solvent then drains downward intotrough 62. Valves 66 and 76 are then opened and the solvent is drainedfrom trough 62 and pumped via pump 70 through lines 68 and 78 to solventstorage tank 48. ()r, if desired, a part or all of the solvent may bepassed through valve 72 and line 74 and disposed of. In the meanwhile,the cardboard workpiece 80 is removed from the gluing station and a newworkpiece is positioned therein. Makeup glue is applied to the glueholding tank 40 through line 42, and makeup solvent is supplied to tank48 through line 50. It will be appreciated that the embodiment justdescribed may be operated intermittently without glue setting orhardening on the disc. Furthermore, the cleaning operation may beaccomplished without any solventbeing sprayed onto the work pieces, orbeing sprayed or dripping onto surrounding machinery.

A preferred embodiment of shield for use in the device of the presentinvention is shown in FIG. 3. In this embodiment the shield comprises agenerally cylindrical drum 82 having a wall comprising substantiallysolid (unbroken) section or area 84, and one or more apertures 86. Theshield is adapted to be moved so that only the apertures are selectiveinterposed in the centrifugal spray path from the disc, while keepingthe solid sections 84 always in the spray path. As will be appreciated,the embodiment just described has an advantage in limiting spray toselected directions.

If desired the device may include means for stopping rotation of disc 20when shield 56 is moving between the first and second positions hereindescribed, and for restarting rotation of the disc when the shield is ineither the first or second position. Such means may include means (notshown) for alternatively starting and stopping the drive means for shaft28. Alternatively, the drive means for shaft 28 may rotate continuously,and there may be included brake 88 and clutch 90 means for alternatelyengaging and disengaging shaft 28 from its drive means.

It will be appreciated that the device herein described may be used forapplying a selected liquid to a flat surface such as cardboard sheet, orit may be used to apply a liquid to the inside walls of an erected structure such as a tube or the like.

Since certain changes may be made in the above system without departingfrom the scope of the invention herein involved, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpretedin an illustrative and not in a limitingsense.

What is claimed is:

l. A centrifugal dispensing device for intermittent application of aselected liquid onto a workpiece comprising in combination: 1

a disc adapted for rotation in a substantially horizon tal plane;

means for selectively discharging either said selected liquid or asolvent therefor onto said disc so that rotation of the latter sprayssaid liquid and solvent in a centrifugal spray path, and

a shield adapted to be selectively interposed between. said disc andsaid workpiece when solvent is being discharged onto said disc, andpositioned to one side of said centrifugal spray path from said discwhen said liquid is being discharged onto said disc.

2. A centrifugal dispensing device as defined in claim 1 including meansfor collecting solvent sprayed onto said shield.

3. A centrifugal dispensing device as defined in claim I wherein saidshield comprises:

a cylindrical, hollow hood mounted about said disc for substantiallyvertical movement relative to the plane of said disc, at least between afirst position wherein said hood is located out of the centrifugal spraypath of said selected liquid from said disc, and a second positionwherein said hood is located in the centrifugal spray path of saidsolvent.

4. A centrifugal dispensing device as defined in claim 3 including anannular trough formed on the inner surface of said hood, and includingmeans communicating with said trough for removing solvent collectedtherein.

5. A centrifugal dispensing device as defined in claim 4 including meansfor recycling at least a portion of said solvent removed from saidtrough for discharge onto said disc.

6. A centrifugal dispensing device as defined in claim 1 wherein saiddisc includes a plurality of generally axially extending, outwardlyflared, distributor vanes.

7. A centrifugal dispensing device as defined in claim 1 including meansfor rotating said disc when said shield is either in a positioninterposed between said impeller and said workpiece or in a position toone side of said path, and for stopping rotation of said disc when whensaid spray path is blocked.

1. A centrifugal dispensing device for intermittent application of aselected liquid onto a workpiece comprising in combination: a discadapted for rotation in a substantially horizontal plane; means forselectively discharging either said selected liquid or a solventtherefor onto said disc so that rotation of the latter sprays saidliquid and solvent in a centrifugal spray path, and a shield adapted tobe selectively interposed between said disc and said workpiece whensolvent is being discharged onto said disc, and positioned to one sideof said centrifugal spray path from said disc when said liquid is beingdischarged onto said disc.
 2. A centrifugal dispensing device as definedin claim 1 including means for collecting solvent sprayed onto saidshield.
 3. A centrifugal dispensing device as defined in claim 1 whereinsaid shield comprises: a cylindrical, hollow hood mounted about saiddisc for substantially vertical movement relative to the plane of saiddisc, at least between a first position wherein said hood is located outof the centrifugal spray path of said selected liquid from said disc,and a second position wherein said hood is located in the centrifugalspray path of said solvent.
 4. A centrifugal dispensing device asdefined in claim 3 including an annular trough formed on the innersurface of said hood, and including means communicating with said troughfor removing solvent collected therein.
 5. A centrifugal dispensingdevice as defined in claim 4 including means for recycling at least aportion of said solvent removed from said trough for discharge onto saiddisc.
 6. A centrifugal dispensing device as defined in claim 1 whereinsaid disc includes a plurality of generally axially extending, outwardlyflared, distributor vanes.
 7. A centrifugal dispensing device as definedin claim 1 including means for rotating said disc when said shield iseither in a position interposed between said impeller and said workpieceor in a position to one side of said path, and for stopping rotation ofsaid disc when said shield is between said positions.
 8. A centrifugaldispensing device as defined in claim 1 wherein said selected liquidcomprises liquid glue and said solvent comprises glue solvent.
 9. Acentrifugal dispensing device as defined in claim 8 including; liquidglue supply means for supplying a predetermined quantity of said glueonto said disc when said spray path is unblocked; and glue solventsupply means for supplying a predeterMined quantity of said glue solventonto said disc when said spray path is blocked.